1. Using the Java Library API
Chapter 6
Using the Java Library API

2. Java API Library API – Application Program Interface
When you install Java, you get hundreds of pre-build classes – the Java Library
Just a giant pile of classes just waiting for you to use
You assemble your own program out of largely pre-built code
The library is full of code you don’t even have to type – just USE IT!!!

3. Example
Import javax.swing.JOptionPane; Public class HelloWorld { public static void main (String[] args) JOptionPane.showMessageDialog(null, “Hello); } } // JOptionPane & showMessage are methods

4. How to discover the java library
Use the web
All of documentation on-line
Google java API
Click on the library
Packages need to be imported
Ex: import javax.swing.JOptionPane
Must import the package
Page of head-first book